An increasing number of external investigators have expressed intersted in MR histology with a specific focus on the rodent brain. The recurring questions are "what can we see anatomically? How can we best see it?" The goal of this effort will be production of a definitive atlas of the rat brain using the standard 3D pulse sequencess. Protocols will be designed to allow comparizon of the various contrast mechanisms (T1,T2, D, T2*). Additional protocols will be desinged to demonstrate the tradeoffs in SNR, resolution, and matrix dimensions (i.e., 256 x 256 x 256 vs. 64 x 512 x 512). Our goals will be a) an abstract for SMR; b) a paper for NeuroImage; and c) a CD for dissemination.